Why Is It Important That the Commentators or Experts Chosen

Why is it important that the commentators or experts chosen are often ex-officials?

A) Their ideas are usually supportive of the political currents of the day.
B) They tend to reflect opinions that differ significantly from those of the party in power in Washington, D.C.
C) It is the best way to create a truly balanced panel of experts.
D) Having worked for the government, they are generally supportive of democracy and freedom of the press.
E) It helps create the most varied set of experts.